1. Field of the Invention
The invention relates to electrical power distribution systems and, more particularly, to surge protection devices for use in such distribution systems, so as to provide for protected circuits, particular circuits of raceways or wall panels or the like.
2. Background Art
Known interior wall systems typically employ pre-fabricated modular units. These units are often joined together in various configurations, so as to divide a workplace into smaller offices or work areas. Generally, such modular wall panels may be equipped with means for receiving general building power and, possibly, general communications. Such building power may, for example, be conventional AC power received either under floor or from relatively permanent walls or the like. In various types of environments comprising electrical equipment, or wherein electrical apparatus are otherwise employed, interconnections of electrical components to incoming utility power are typically provided by means of cables or wires. For example, in office systems compromising modular furniture components, it is often necessary to provide electrical interconnections between incoming power supplies and various types of electrical devices typically used in an office environment, such as electric typewriters, lamps, etc. Computer-related devices, such as video display terminals and similar peripherals, are also now commonly employed in various office and industrial environments.
One advantage inherent in modular office systems is the capability to rearrange furniture components as necessitated by changes in space requirements, resulting from changes in the number of personnel and other business-related considerations. However, these modular systems must not only allow for change in furniture configurations, but also must provide for convenient interconnection of electrical devices to utility power, regardless of the spacial configuration of the modular systems and resultant variable distances between electrical devices.
In providing the interconnection of electrical apparatus and power inputs, it is necessary to include an arrangement for feeding the incoming utility power to the power outlets. In stationary structures, such as conventional industrial buildings and the like, a substantial amount of room would normally exist behind stationary walls and other areas in which to provide the requisite cabling for interconnecting incoming utility power to electrical receptacles mounted in the walls. Such systems, however, can be designed so as to remain stationary throughout their lifetime, without requiring general changes in the office or industrial environment areas.
In addition to receiving electrical power from the general incoming building power supply, modular office systems typically require communications connections for office equipment such as telephones, internet communications and the like. The problems associated with providing distribution of communications essentially correspond to the same problems existing with respect to distribution of conventional electrical power.
In this regard, it is known to provide modular wall panels with areas characterized as raceways. Often, these raceways are located along bottom edges of modular panels. The raceways are adapted to house electrical cabling and electrical junction blocks. The cabling and junction blocks are utilized to provide electrical outlets and electrical power connections to adjacent panels. However, it is also apparent that to the extent reference is made herein to providing electrical outlets and electrical power connections for adjacent panels, the same issues exist with respect to providing communications among panels.
Still further, it is known that the raceway of one modular wall unit may be provided with a male connector at one end, and a female connector at another end. Pairs of junction blocks, each provided with electrical outlets, made to be disposed at spaced-apart positions along the raceway. Conduits may be extended between the junction blocks and between the connectors in the junction blocks. In this manner, electrical interconnection is provided between the units.
The modular panels of a space-divider may be configured, such that adjacent panels are in a straight line, or at various angular positions relative to each other. It is common to configure intersecting walls in such a fashion that three or four modular wall panels may intersect at right angles. Each of the panels typically requires electrical outlets, and may require outlets on both sides of the panels. In any event, electrical power has to be provided to all of the panels, and often only one of the panels at the multiple panel junction is connected to a power supply source.
One example of a prior art system is illustrated in Propst's, et al., U.S. Pat. No. 4,382,648 issued May 10, 1983. In the Propst, et al. system, mating connectors of opposing panels are engaged when the panels are aligned in a straight line. When the panels are positioned in an intersecting relationship, specially manufactured couplers are utilized. One type of special coupler is used when the panels are positioned at right angles. Another type is used with adjoining panels arranged at angles other than right angles. Consequently, costly inventory of couplers must be maintained. The Propst, et al. system uses a double set of connectors comprising a male and female connector for each conductor to be interconnected. When a single one of these prior art panels intersects two adjacent panels, one of the specially manufactured couplers connects the female terminals to one of the adjacent panels, and another of the couplers connects the male terminals to the adjacent panel.
A further system is disclosed in Driscoll, U.S. Pat. No. 4,135,775, issued Jan. 23, 1979. In the Driscoll system, each panel is provided with an electrical outlet box in its raceway. Panels of different widths are provided with a pair of female connectors. Outlet boxes of adjacent panels are interconnected by means of flexible cables having male connectors at both ends. When three or four panels are adjoined in an intersecting arrangement, two cables may be connected the pair of female connectors at one end of an outlet box. In this manner, connection of two adjacent panels is facilitated.
Other systems also exist with respect to electrical connectors, junction boxes, and the like. For example, Rodrigues, U.S. Pat. No. 1,187,010 issued Jun. 13, 1916, discloses a detachable and interchangeable electrical switch plug adapted for use in connection with various electrically heated appliances. A clamping device is positioned in a fixed, but detachable relationship to one end of the plug. Means are provided to enclose and prevent sharp flexure of the cord comprising a flexible enclosing tube gripped under tension by the other end of the clamping device. The plug and the clamping device may be simultaneously removed from the socket.
Finizie, U.S. Pat. No. 2,540,575, issued Feb. 6, 1951, discloses a cord guide member for utensil plugs. The concept is to reduce wear on the cord and the connector plug, and to provide a connection which will withstand heavy pulling strains without injury. Strain relief is also provided. A sectional body is equipped anteriorally adjacent one end of the body with terminals. The other end of the body contains an anterior chamber or socket. A pivotable cord-guiding member having a pivot member is movably mounted in the socket. A wedge-shaped strain relief insert is received within a wedge-shaped recess in the pivot member. A cord extends into the pivot member and includes wires passing from the cord toward the terminals. The incoming portions of the wires are moved around the insert and firmly wedged within the recess.
Byrne, U.S. Pat. No. 4,551,577, issued Nov. 5, 1985, describes a retractable power center. The power center provides for conveniently located electrical power source receptacles adapted to be mounted on a work surface. In one embodiment, the power center includes a rectangular housing received within a slot in a work surface. A clamping arrangement is utilized to secure the housing to the work surface. A lower extrusion is connected to the lower portion of the housing. A movable power carriage mounts the receptacles and a catch assembly releasably maintains a carriage in a closed and retracted position. In response to manual activation, the catch assembly is released and springs tensioned between the carriage and the extrusion exert forces so as to extend the carriage upward into an extended, open position. In the open position, the user can energize the desired electrical devices from the receptacles, and then lower the carriage into the retracted position.
Byrne, U.S. Pat. No. 4,959,021, issued Sep. 25, 1990, discloses a pivotable power feed connector having a pivotal connector adapted to be connected to a flexible conduit or cable. The cable has a series of conductors extending there through. The connector is pivotably connected to a block assembly through which the conductors extend. The block assembly, in turn, is connectable to a contact block, with the conductors conductively connected to a set of prong terminals extending outwardly from the block. A cover is secured over the block so as to prevent the prong terminals from being exposed during assembly and disassembly.
The cover automatically exposes the prong terminals as the power feed connector is moved into engagement with a receptacle in a modular office panel. The connector allows the conduit or cable to be swiveled to an arc of approximately 180 degrees to any desired position. The connector is also manually removable from interconnection with the block assembly. Such removal allows the conduit or cable to be pulled back from the conductors and cut to a desired length. The connector includes a power feed cover which can be utilized in part to maintain the connector in either of two spatial configurations relative to the block assembly.
Nienhuis, et al., U.S. Pat. No. 5,013,252, issued May 7, 1991, discloses an electrified wall panel system having a power distribution server located within a wall panel unit. The server includes four receptacle module ports oriented in an h-shaped configuration. A first receptacle port is located on the first side of the wall panel unit and opens toward a first end of the unit. A second receptacle unit is also located on the first side of the wall panel unit, and opens toward a second end of the wall panel unit. A third receptacle port and a second sided wall panel unit opens toward the first end of the wall panel unit, while correspondingly, a fourth receptacle port on the second side of the wall panel unit opens toward the second end of the wall panel unit. First and second harnesses are each electrically connected at first ends thereof to the power distribution server. They extend to opposite ends of the wall paneled unit and include connector ports on the second ends thereof for providing electrical interconnection of adjacent wall panel units. The Nienhuis, et al patent also discloses a system with a wall panel connector interchangeably usable with the interconnection of two, three or four units. The connector includes a hook member for connecting together adjacent vertical members of frames of adjacent wall panel units at a lower portion thereof. A draw naught for connecting together adjacent vertical members of frames of adjacent wall panel units and an odd proportion thereof is provided by vertical displacement thereof.
Lincoln, et al., U.S. Pat. No. 5,073,120, issued Dec. 17, 1991, discloses a power distribution assembly having a bussing distribution connector. The connector includes a series of bus terminals positioned within an electrically insulative housing. A series of electrical terminals are positioned in the housing for distributing more than one electrical circuit. At least one ground terminal, one neutral terminal, and three hot terminals are provided. A grounding shell partially surrounds the bus connector and includes a grounding tab grounding the one ground terminal to the metallic grounding shell. In another embodiment, two bus connectors are interconnected together, so as to provide for an increased number of output ports.
Byrne, U.S. Pat. No. 5,096,431, issued Mar. 17, 1992, discloses an outlet receptacle with rearrangeable terminals. The receptacle is provided with input terminals to selected positions, for engagement with terminals of an electrical junction block. The block includes a series of terminals representing a plurality of different electrical circuits. The receptacle block has neutral, ground and positive flexible positive conductor bars electrically connected to neutral, ground and positive electrical terminals. Input terminals of the block are formed integral with the flexible conductor bars and levers are provided for moving the terminal ends of the conductor bars to physically different positions. In one configuration, the receptacle block housing is provided with openings at opposing ends, and the flexible conductor bars have terminal ends controlled by levers at both ends of the outlet receptacle block. In another configuration, the block has output terminals in a front wall, and the input terminals of the receptacle block are formed as ends of the flexible bars and extend at an approximately 90 degree angle to the bars. They further send through openings in the back wall of the outlet receptacle for engagement with terminals of a junction block. Levers are provided in the back wall of the receptacle block for positioning the terminal ends in alignment with different terminals of the junction block, and windowed openings in the front wall expose indices on the levers identifying selected circuits.
Byrne, U.S. Pat. No. 5,096,434, issued Mar. 17, 1992, discloses an electrical interconnection assembly for use in wall panels of a space divider wall system. The system includes junction blocks having several receptacle connectors, so as to provide a plurality of electrical outlets on both sides of a wall panel. The junction block is connected by means of conduits extending from both ends of the junction block to oppositely directed connector blocks for connection to adjoining panels. The assembly of the junction block and connector blocks allows electrical power to be supplied to one end of the panel and conducted to and through the junction block to other panels. The receptacle connectors on the junction block each have one type of terminal configuration, e.g., a female electrical terminal configuration. One of the connector blocks is provided with the identical terminal configuration. The other connector block is provided with a matching terminal configuration, e.g., a male electrical terminal configuration. When two wall panels are joined at their respective edges, the male connector block may be readily connected to the female connector block in the adjacent panel. When two panels are joined to a third panel, all at one point, the arrangement of this invention allows the male connector block to be connected to the female connector block of one of the other two panels, and the male connector of the other of the two panels may be connected to one of the receptacle connectors of the junction block on either of the other two panels, in this manner establishing a three way interconnection arrangement. In a similar fashion, a fourth, or other additional panels may be added to the junction and plug into receptacle outlets of other panels in order to provide an arrangement of panels that is totally interconnected, electrically.
Snodgrass, et al., U.S. Pat. No. 5,164,544, issued Nov. 17, 1992, describes an electrified space dividing panel having a panel member, raceway, modular, or electric system disposed in a raceway and raceway covers for gaining access to the system. The system includes a single terminal block having end and side sockets, with first and second electrical receptacles being respectively removeably engaged with the end socket and the side sockets, such that the first and second electrical receptacles are disposed in horizontally spaced, side-by-side relation and project outwardly for predetermined light dimensions through receptacle openings in one of the raceway covers. The raceway can include a web having an opening which cooperates with a support ear on the first receptacle during engagement of the first receptacle with an end socket, so as to provide additional lateral support for the electrical receptacle when a plug is removed there from.
Kilpatrick, et al., U.S. Pat. No. 5,178,555, discloses a kit which includes a junction box for installation along a raceway. The kit includes a mounting bracket having a first adjustable mounting mechanism for locating the bracket along the raceway. This provides an initial adjustment, and a second adjustable mounting mechanism is provided for securing the junction box to the mounting bracket. This adjustably locates the junction box along the mounting bracket, and provides a second or final adjustment to accurately locate the junction box between two pre-measured lengths of cable.
Byrne, U.S. Pat. No. 5,259,787, issued Nov. 9, 1993, discloses an electrical junction block mounting assembly, which may be utilized for mounting the junction block within a raceway. The assembly includes a cantilever beam formed on an outer wall of the junction block. This beam is provided with a transversely extending channel for engagement with a support structure. The beam is attached to the junction block by means of a resilient hinge section, and is provided with a first arm section extending between the hinge section and the channel, and a second arm section extending beyond the channel. The first arm section has a sloping surface sloping away from the outer channel between the hinge section of the panel. The second armed section has a sloping surface sloping toward the wall beyond the channel. The surfaces will contact a mounting rail or similar structure during installation of the junction block. In this manner, the hinged cantilever beam is deflected until the rail is in alignment with the channel for engagement with the structural support member.
Also advantageous for power distribution systems utilized with raceways and the like is the concept of potentially providing for surge protection. Principles of surge protection circuits are relatively well known in the art. However, the concept of providing for surge protection can sometimes lead to difficulties associated with providing for such protection within relatively confined spaces, such as may exist with raceways within wall panels or the like. Also, it is advantageous if surge protection devices allow the user to select whether a circuit is to be protected by such a surge protection device or, alternatively, left unprotected. In certain instances, where a series of circuits may exist within a single raceway, it would be advantageous if a surge protector could be utilized which would have the capability of selecting which of these circuits are to be protected.
An example of a power surge protector utilized in a system comprising modular wall panels is disclosed in Eaton, et al., U.S. Pat. No. 5,412,529 issued May 2, 1995. Eaton discloses a modular wall panel assembly having a concealed and pre-wired electrical system associated therewith. The system comprises a multi-wire powerway defining at least one power circuit, with the powerway preferably defining multiple power circuits. The powerway is coupled to at least one surge protector disposed interiorly in the wall panel member, and providing power protection to a power circuit thereof. The surge protector comprises either a power surge protector or an uninterruptible power supply. A powerway is disclosed which has at least two power circuits having power circuit receptacle terminals constructed so as to allow a compatible receptacle element to be selectively positioned on the powerway, in a power delivery relationship with any of selected ones of the multiple power circuits.
Ahuga, U.S. Pat. No. 6,157,529 issued Dec. 5, 2000 discloses a basic surge protector for protecting electrical equipment connected on its load side from excessive transient voltages or surges above a predetermined value, on its line side or its hot side. A fuse is used to monitor a fault current flowing into a surge voltage suppression device, due to excessive voltage across the device. The fuse blows resulting from an over current condition, and disables and opens a solid state switch or an electromechanical switch mounted in series in the line. In this manner, the secondary or load side is protected from over voltages and surges. Ahuga also discloses circuits providing for automatic setting and resetting after an over voltage fault condition on the line has been protected. The protection device can be rendered into a single chip, solid state device.
Waas, U.S. Pat. No. 6,188,560 issued Feb. 13, 2001 describes a multi-wire terminal block employing a removable surge protector. The block has a housing with a series of test ports and electrical contact elements. Each includes a test lead accessible through one of the tests ports. The contact elements are configured in the housing and connected to an exchange wire which is secured to a stub cable. A protection module is secured to a side of the housing adjacent the test ports so as to form a series of retaining cups adapted to receive a protection module. A grounding strip is secured to ground and retained between the protection module retainer and the housing adjacent the test ports. The grounding strip includes a series of integral ground connectors. The protection module includes a protector connected to a pair of terminal block contact elements and a ground connector. When inserted into the retaining cup, the contact elements engage a pair of corresponding test lead and test ports. The ground connector engages a grounding strip so as to provide surge protection to a pair of conductive paths through the connection of the leads in the ports. The protection module may be removed or replaced as needed.
LaHoud, U.S. Pat. No. 6,266,220 issued Jul. 24, 2001 discloses an internal surge protection device for an electronic component. The device is primarily directed to electronic elements which may be associated with circuit boards.
Wohlgemuth, et al., U.S. Pat. No. 6,369,999 issued Apr. 9, 2002 discloses a portable surge protector having a housing with a central opening and an internal cavity surrounding the opening. By rotation of a mounting reel, a cord moves between a closed position within the housing to an extended position outside of the housing. An electrical connector is pivotably supported in the central opening housing and has at least one socket and a set of prongs that extend outwardly from the socket. The connector can be rotated to a first position normal to the housing, in which the prongs and the socket are exposed for use, or to a second position parallel to the housing, in which the socket and prongs are recessed.
Karim, et al., U.S. Pat. No. 6,380,862 issued Apr. 30, 2002 discloses an electrical distribution panel having a surge protector. The distribution panel is associated with a load center and includes an enclosure having a window and a series of openings. Inputs are adapted for connection to power lines. A circuit breaker mounting mechanism houses a series of circuit breakers in association with corresponding ones of the enclosure. A surge protector device is mounted within the enclosure apart from the mounting mechanism. The device is electrically connected with the inputs for protecting the loads from surges or transients on the power lines. The surge protector device includes at least one indicator, visible through the window of the enclosure.